| 摘要 |
PURPOSE:To offer an information transmitting system having high reliability even at a disaster such as earthquake without requiring any electric wiring by propagating an ultrasonic wave signal in a gas pipe installed already to transmit information. CONSTITUTION:If leakage of gas takes place near a gas device using section (k) because of a failure in a gas device B1 or B2, a gas sensor D detects said leakage and a gas leakage alarm device C is operated, then an ultrasonic wave transmitter E is operated and the ultrasonic wave signal is issued from a transmitter F. This ultrasonic wave signal reaches a wave receiver G of a main valve section J via a T path c1, an L path b1, a T path c2, and an L path b2 of the gas pipe A to operate the ultrasonic wave receiver H, a solenoid valve I is driven and the gas is interrupted. When the gas or air in the gas pipe is utilized as the transmitting medium, since the transmission is done through the enclosed space, no effect of ultrasonic wave noise at a free space exists, and the transmission efficiency is equal to that in a free space or over. When the gas pipe wall is utilized as a transmission medium, a failure in the gas pipe itself due to mechanical shock is detected. |
